Claudia is a bit confusing on the pronounciation side, IMO, because there's different languages that use it: "CLAU-di-ya" or "CLAW-di-ya" are both common. I think the first is prettier, but in the USA the 2nd will be what most people actually say. I really don't prefer Claudie, it just sounds like an annoying poodle name to me. (Sorry!)

Calista is lovely but to me it's still tied primarily to Calista Flockhart, so I have a mental block about it. I LOVE the nn Callie, though. It's so down-home, pioneer/Southern sounding to me. But I like having a fuller, a bit surprising full name like Calista behind it.

Camilla is nice but I actually prefer Camille. I voted for it mainly because I ADORE Millie.